Giving tissue plasminogen activator to patients suffering a stroke who have been taking aspirin or the anticoagulant clopidogrel is not likely to cause fatal brain bleeding, a study published in the journal Academic Emergency Medicine found. Researchers examined data from more than 800 tPA-treated stroke patients and found no significant difference in the brain bleeding rate between patients taking clopidogrel or aspirin and those not taking either drug. The findings might not apply to patients taking warfarin, heparin, dabigatran or rivaroxaban, researchers noted.